1990 chevy 4×4 s-10 4.3 blazer

Hi, I am looking for a little advice. I’ve had “Red” for about 12 years now she’s been in times our most reliable ride. I’ve done almost all of the repairs on her myself with help from youtube and Eric’s vids. Mostly easier stuff,ie. water pump, heater core, u-joints, new gas tank and feul pump, muffler, starter, tranny gasket, and I do all my own oil changes and schedualed maitenence. Oh, even a new radiator about 2 years ago. Recently I had to replace my power window controller/harness whatever. I wired it exactly how it came out, but now the pass window doesn’t work and the driver side is in reverse, I’ll deal with that in a bit. For now I haven’t been driving her for almost a year and as of two months ago she won’t start And I’m not getting any power from the batt. Nothing. I’ve checked the fuses and seem to be getting continuity, it’s also a new battery, checked today and the batt has not enen a volt, had it on a trickle for two days, still nothing. Any way this is in the mod topic. I plan on getting her on the road by january and I’d like to clean and paint the headers and manifold, maybe upgrade the throttle body and hood for a meaner look but before I get into that, I can’t get her to run and I’m like what the F? any sugestions would be great. thank you ahead of time.